Self-adhering labels have become very popular for use in the decoration, general-purpose marking and identification of manufactured objects. Also referred to as "stickers" or "decals", the use of these labels continues to grow with more demand being placed upon the design and manufacture of the label material to provide increasingly unique and complex structures. As a result, labels are now printed with one or more types of eye-catching graphics in order to capture consumer attention and create a unique product image.
Holographic or prismatic materials are extensively used as label stock to attract attention with dazzling reflections of refracted light bouncing off the embossed patterns in the material surface. One industry in which these labels are heavily used is the beverage industry wherein the labels may be placed over the exterior of glass or polyester (PET) bottles. Furthermore, the cosmetic food and pharmaceutical industries also place a high value on eye-catching and attractive labeling of their goods.
The visual complexity of these materials has also been exploited to create labels and other marking media that provide evidence of counterfeiting or tampering with the objects on which labels are placed. The tamper-evident nature of prismatic or holographic media rising from the inherent difficulty in copying them also favors their inclusion in these types of labeling materials.
However, one problem with the typical prismatic materials used to form the above-mentioned labels is that the materials tend to be opaque since they are metallic in appearance. The opaqueness of the material detracts from the ability of a consumer to see the contents of the object through the label when placed on the object. Therefore, it is desirable to use a prismatic material to decorate an object that retains some clarity so that one may see through the label and into the contents of the object.
Furthermore, a second problem with prior art material labels arises with respect to the way that the labels are made. Prior art prismatic labels are normally formed entirely of a prismatic film or may include only a section of prismatic material placed on the label by way of stamping a predetermined area of the label with a prismatic or holographic foil. The prismatic materials used to form these labels tend to be expensive due to the multiple-step processes used in producing the embossed and metallized film that will eventually be converted into individual labels.
Therefore, it is desirable to develop an alternative label construction or adhesive composition for use in creating labels for various objects that incorporates some prismatic features to provide a striking, distinctive appearance to the object at a reduced cost, which is also substantially transparent or clear to enable a consumer to view the contents of the object through the label.